Vehicle Seat Piston Restraint for Submarining Prevention
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Solution Overview
Problem
In vehicles using human-assisted driving technology, the traditional seat belt system, which relies on the vehicle body for support, becomes less effective due to increased seat adjustments, leading to reduced safety and increased risk of submarining during frontal crashes.
Innovation Solution
A seat restraint system featuring a piston-based restriction arrangement that moves from a retracted to an extended position to abut a stopper, restricting the pivotal movement of the seat frame, activated by a crash sensor, providing enhanced control over downward and forward movements and ensuring earlier occupant coupling with the seat belt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the seat frame is made adjustable in height and longitudinal direction to improve comfort and entertainment system accessibility, then the adaptability of the vehicle seat is improved, but the reliability of the seat belt restraint system deteriorates due to misalignment with connecting points
Solution Approach 1:
The piston is pre-positioned in a retracted state during normal operation, and the restraint function is activated preliminarily through the activation signal upon detection of a crash event, enabling the seat frame to be restrained at the optimal position before the crash forces act on the occupant
Solution Approach 2:
The seat restraint system transitions from a static configuration to a dynamic one by moving the piston from retracted to extended position upon activation, allowing the system to adapt its restraint characteristics based on the crash event while maintaining adjustment flexibility during normal operation
2Ease of operation
If the seat frame is allowed free pivotal movement to accommodate various seating positions, then the ease of operation is improved, but the safety during frontal crash deteriorates due to increased forward movement of the seat back
Solution Approach 1:
The piston acts as an intermediary mechanical element between the seat frame and the external restraint system, providing controlled resistance to pivotal movement during normal operation while enabling full movement freedom, and activating to restrict movement upon crash detection to prevent submarining
3Reliability
If a restriction arrangement with piston is added to control seat frame movement, then the safety during crash is improved, but the device complexity increases
Solution Approach 1:
The piston-based restriction arrangement serves multiple functions: it allows free movement during normal operation, provides controlled restraint during adjustment, and activates to prevent submarining during crash, making a single component perform multiple safety functions across different operating conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively reduces the risk of submarining and enhances overall safety by maintaining the seat's position during crashes, ensuring the seat belt engages the occupant more securely and distributing loads effectively across the vehicle seat.
Implementation Method 1
a piston which is arranged in a cylinder chamber, said piston being displaceable in an extension direction by a pressure applied to said cylinder chamber
Data Source
Figure 1a
Figure 1b
Figure 2a
AI summary
A vehicle seat (1) with a seat restraint system (100) is provided. The vehicle seat (1) comprising a seat frame (2) which is adjustable in a height direction and in a longitudinal direction; a stopper (101); and a restriction arrangement (102) comprising a piston (103). The restriction arrangement (102) is configured to, upon an activation signal, move the piston (103) from a retracted position to an extended position in which a free end of the piston (103) abuts the stopper, thereby restricting a pivotal movement of a front end portion (104) of the seat frame (2). Also, a method of restraining a pivotal forward movement of the front-end portion of a seat frame (2) is provided.